The Steadicam.RTM. camera stabilizer has become a mainstay of the motion picture and video industries (see U.S. Pat. Nos. Re. 32,213; 4,017,168; 4,156,512; 4,208,028; 4,474,439; 5,360,196; 5,435,515; and 5,579,071, the teachings of which are incorporated herein by reference). The camera stabilizer comprises an expanded camera support (i.e., the "sled"), an operator vest, and an articulated equipoising arm that is attached between the vest and a three-axis gimbal on the camera support. The Steadicam.RTM. camera stabilizer permits a camera operator (carrying a camera) to walk, run, climb stairs, etc., while maintaining a stable image. It received an Oscar for Scientific/Technical Achievement in 1978. In the intervening years, a number of problems and new opportunities have been identified, which have not yet been resolved or facilitated by existing Steadicam.RTM. equipment.
Since 1979, operators have routinely operated the Steadicam.RTM. camera stabilizer with the sled inverted, so that the camera is on the bottom and the battery, monitor, etc., are on top. This maneuver facilitates "low-mode" operation which allows the camera lens height to be anywhere between the waist and the knees of the operator. However, it is frequently desirable to have the lens much lower. And in normal "high-mode" operating, with the camera on top, it is frequently desirable to have the lens considerably above the operator's head. Since 1985, to facilitate both of these objectives, operators have fashioned extra-long 72-inch "super-posts" to replace the normal-sized main post of the conventional Steadicam.RTM. camera stabilizer. The use of an extra-long post allows for lens heights in low-mode right down to the ground, and, in high-mode, up to nearly 8 feet in the air.
The problem with this arrangement is the time it takes to switch over from the conventional Steadicam.RTM. camera stabilizer configuration, and the cost of the components that are owned in duplicate in order to prevent even more time-consuming operations. All super-post designs presently offered to operators require 20 or more minutes to install, even if the operator owns an extra gimbal and even a extra "stage" (i.e., the adjustable mounting platform for use in attaching and positioning various cameras).
In order to make this changeover, operators must presently disconnect and remove the camera, disassemble the sled, reassemble, re-install, reconnect, etc., and the result is that operators and their clients dread the time taken to change over to (and back from) ultra high-mode or ultra low-mode shooting. Furthermore, operators must frequently spend fifteen thousand dollars or more in order to carry the extra equipment required to prevent even further waste of time.
Note that it is impractical to maintain the Steadicam.RTM. camera stabilizer, in the "super-post" mode all the time for two reasons: The Steadicam.RTM. camera stabilizer is easier to operate, particularly for rapid moves in close quarters, when it is in its compact normal mode. For routine shooting in this normal mode, the rotational inertia of the sled in the tilt axis is more closely matched to its inertia in the pan axis, which makes it easier to use. Also, because of its enormous length, the "super-post" mode makes it impossible to achieve the most common range of lens heights, which are between the knees and head of the operator.
A further difficulty with existing super-post designs is that even the stiffest carbon-fiber post designs are prone to vibration and "whipping" during high-speed running, violent maneuvers, or shots made while riding in bumpy vehicles.
Problems have also arisen with existing super-post designs, because, with light cameras and corresponding lower gimbal positions (the gimbal needs to be at the center of gravity), the range of monitor positions providing an acceptable line of sight for the operator is severely restricted.
There is another mode of shooting that has always been problematic. A number of operators also own and supply a "running" rig which consists of a dedicated "sled" with a lightweight monitor and battery, so that it will appropriately counterbalance the lightest available camera to facilitate running shots at top speed. These kinds of shots can be dangerous when carrying the 70+ pounds of the conventional Steadicam.RTM. rig with all accessories. If an operator owns duplicates of all the necessary components, he or she can have a lightweight running rig standing by for nearly immediate use. However, according to today's most common usage, a large number of ancillary components must also be duplicated and mounted for this purpose, such as a remote video transmitter so the director can watch the shot in progress, and additional wireless focus-pulling equipment so that the camera assistant can adjust the focus of the lens. Therefore, an operator must either be resigned to spending a lot of time or a lot of money in order to provide this running rig to his clients.
U.S. Pat. No. 5,579,071 discloses the sled of what is marketed as the "Master Series" Steadicam.RTM. camera stabilizer. It provides for quick changeovers, such as low-mode, and for other common adjustments without the use of tools, by providing special finger-operated clamps and locking knobs. With the Master Series sled, an operator can change over to low-mode in seconds-an operation that formerly used to take 10 minutes or more--and can adjust the bottom-heaviness of the sled by moving the gimbal/handle assembly up or down on the post in just a second or two. This "no-tools" philosophy is applied to every operation on the Master Series equipment, including adjustment of the lifting strength of the arm and of the fit of the vest.
Like most Steadicam rigs, the Master Series rig comes with an expandable post, but its range is severely limited because of the need for the sled to be at a normal size for most shooting. Therefore, even at maximum expansion, the post only lowers or raises the range of lens heights available to the operator by a few inches.
The Master Series equipment provides for increasing and decreasing the rotational inertia of the sled by spreading out the principal masses--by pulling the monitor forward and the battery rearward. This is a useful feature, but constraints of the present configuration of the sled mean that the amount of travel of monitor and battery is quite limited.
Available Steadicam.RTM. designs do not provide for independent tilting of the camera. As a result, operators have long endured a number of consequences: In 90% of operating situations, lens heights are maintained above the waist level of actors, and therefore the Steadicam.RTM. is normally carried with a slight (3.degree. to 5.degree.) down tilt to accomplish proper framing and "headroom". This has required the whole "sled" (the entire camera support structure) to be tilted, causing a number of problems. Steadicam.RTM. sleds are carefully adjusted to be in dynamic balance so that when panned, they spin around the true axis of the central post without precession. This becomes meaningless and counterproductive, when the sled centerpost is not held vertical, since panning now requires this axis to artificially precess around true vertical. In addition, maintaining this perpetual tilt frequently causes physical interference when operators "switch" the equipment from one side of the body to the other, since such a move is more likely to be obstructed by the Steadicam.RTM. arm hardware when the sled is tilted down and its lower components are therefore displaced to the rear.
In other cases, more radical tilts up and down have always required correspondingly radical tilts of the entire sled, particularly with long-post operation. Such radical tilts mean that the height of the camera enabled by the long post is immediately reduced because of its arcuate swing forward when the entire long sled is tilted. Of course this also exacerbates the clearance problems encountered when moving through tilt quarters on a set because the post now sticks out considerably, both in front of and behind the operator.
One reason that tilting heads have not been devised previously for Steadicam.RTM. is that use of known designs would tend to cause additional problems. The functioning, for example, of conventional tripod-head-type tilt mechanisms would cause violent changes in the position of the camera's center of gravity, thus requiring elaborate rebalancing. Even the use of known special tripod-head designs that rotate about a point directly above their mounting centerline would unacceptably shift the camera's center of gravity (c.g.) when functioned, since in Steadicam.RTM. applications, dynamic balance usually requires that the camera's c.g. be nominally one inch aft from the centerline of the main Steadicam.RTM. post. Also, such designs, insofar as is known, would all require excessive size and weight in order to provide for as much as 20.degree. of tilt up and down. Their excessive depth would restrict the range of gimbal positions near the top of the post which are employed to balance the heavier cameras. Also, such conventional tilt heads would obstruct access to any clamps or hardware positioned high on the post just below the camera.
Another problem, even with previous small telescoping posts is getting the internal electrical wires to retract without fouling when the posts are fully shortened.